Abnormalities in tongue strength, range of motion, and coordination are primary contributors to speech deficits resulting from stroke, head injury, neuromuscular disease, oral cancer, and developmental delays. Despite the fact that tongue contact with the hard palate is a critical event for normal speech production, data regarding the strength of that contact during speech are limited. The goals of this project are to refine procedures for measuring linguapalatal contact pressure (LPCP) during speech and to gather LPCP data from individuals with unimpaired speech. Specific aims (SA) of the project are to: 1) determine a suitable transducer for measuring LPCP during speech, 2) identify the method of transducer adhesion in the mouth that interferes least with speech, 3) determine the accommodation period speakers require to adjust to the measuring device in the mouth, 4) describe LPCP variation as a function of various speaker behaviors, and 5) evaluate the relationship between LPCP, oral air pressure (P) and linguanalatal contact area (LPCA). Once the methodological issues are resolved, future work involving LPCP measurement will: 1) lead to a more complete understanding of speech production, 2) allow normative data collection to serve as a referent for individuals with disordered speech, and 3) lead to the development of a useful research and clinical procedure to improve the diagnosis and treatment of individuals with speech impairments. SA1 will be achieved by evaluating the response characteristics of two subminiature pressure transducers that appear suitable for LPCP measurement (Experiment 1). This will include transducer performance during speech production. To accomplish SA2, two methods of placing the transducer in the mouth (tape adhesion versus palatal mold mounting) will be compared in Experiment 2. The degree of speech distortion that each method induces will be gauged by evaluating listener perceptions, speaker perceptions, and acoustic features of the productions. SA3 will be met in Experiment 2 by recording speakers at set time intervals with the transducer in place and evaluating changes in listener perception of the speech across the time intervals. SA4 will be addressed in Experiment 3 when LPCP magnitude and variability will be described for a set of consonants spoken by individuals who will systematically vary speech rate, loudness, and articulatory precision. These production parameters are often manipulated therapeutically for individuals with speech deficits. SA5 will be achieved by evaluating the relationships between LPCP, P/o, and LPCA measures simultaneously recorded from individuals with unimpaired speech. Clearer understanding of the relationship between these measures will allow a more complete understanding of speech production, and lead to a larger research application dealing with speech dynamics.